a) Field of the Invention
This invention relates to a new or improved sectional door structure and to a novel door panel for use therein. The specific embodiment of door structure disclosed herein is designed as a wind door for use in an automatic car wash, but clearly it would be adaptable for use in numerous applications wherein a reliable rapidly operating door structure is required.
b) Description of the Prior Art
Particularly in extremely cold climates, it is desirable to provide in an automatic car wash both entry end and exit end wind doors which will open and close rapidly to permit passage of cars through the doorways, but otherwise will present a substantial barrier to the entry of large volumes of extremely cold atmospheric air which would cause serious problems if it were to bring about freezing of the numerous water pipes and nozzles in the car wash. Such a wind door must be designed to be safe and reliable in operation and should be of such a nature that it will not damage an automobile should it accidentally come into contact with one. Furthermore, for safety reasons a wind door should be substantially transparent.
In one known form of wind door commonly used in automatic car washes, there is a series of vertically elongated rectangular strips of clear plastic material, each supported at its upper end in a carrier that can rotate about a vertical axis and can be moved longitudinally in a guide, spanning the top of the doorway. In the closed condition the carriers are spaced uniformly along the guide rail and are oriented such that the panels are essentially complanar and slightly overlapping, thus forming a substantially continuous door structure. In the wind door at the exit end of the car wash, the lower ends of the panels are sometimes provided with a covering of heavy felt material, the panels being substantially flexible so that when they are in the closed position, an automobile can pass through the doorway and exit the car wash, the lower ends of the panels being displaced to accommodate this, and in the process the felt material thereon wiping across the surfaces of the automobile and serving to remove excess moisture.
A significant problem with doors of the above described kind is that they do not form a very efficient seal since the lower ends of the panels are unconnected, and therefore the panels can flap about quite freely in response to gusts of air, thus creating significant openings through which cold air can enter the car wash. Additionally, because of their flexibility and unrestrained swinging action, the separate panel sections often clash together so that although originally of substantially clear material, their transparency is gradually degraded over time until eventually they become merely translucent.